Nesting switch for submunition fuzes

ABSTRACT

A nesting switch is disclosed that is used to sense that the submunitions of an explosive ordnance have been removed, unnested, or unstacked from their storage locations. The nesting switch, in one embodiment, has at least one contact that is stationary and another contact which sticks out and interferes with the submunitions so as to be compressed against the stationary contact while the submunitions is in a storage (non operative) location and, then if the submunition is removed the interfering contact moves away from the stationary contact causing the generation of an unnested control signal that is delivered to the system controlling the fuze of the submunitions. The nesting switch is another embodiment that has a lever that sticks out and interferes with the submunition so as to be compressed causing another part of the lever to come in contact with the electrical contacts.

STATEMENT OF GOVERNMENT INTEREST

[0001] The invention described herein was made by an employee of the United States Government and may be used by or for the government for governmental purposes without the payment of any royalties thereon or therefor.

BACKGROUND OF THE INVENTION

[0002] 1.0 Field of the Invention

[0003] This invention relates to impact explosive ordnance and, more particularly, to a switch for detecting the unstacking event of nested submunitions of the explosive ordnance.

[0004] 2.0 Description of the Prior Art

[0005] Explosive ordnance in the form of a projectile, typically carry submunitions (grenades) that remain in a stacked or inoperative state during flight and, then upon predetermined time are unstacked to obtain their active state. It is desired that a reliable mechanism be provided to detect the stacked (nested) or unstacked (non-nested) condition of the submunition so as to properly respond thereto. More particularly, it is desired that a nesting switch be provided that detects the unstacked/stacked conditions of submunitions.

[0006] In an explosive ordnance, it is important to minimize the storage area for the submunitions so as to improve the overall range of the explosive ordnance carrying the submunitions and thus, its performance. Similarly, it is important to reduce the space required by a nesting switch to perform its operation so that the overall storage locations may be correspondingly reduced. It is desired that a nesting switch be provided that occupies a minimum region to perform its operation.

[0007] Because of the importance of the function performed by a nesting switch, it is desired that it be provided having a fail safe operation, that is, the active state of the nesting switch may be used to provide the normal indication of the nested submunitions, while as the inactive or dormant state of the nesting switch be used to provide the abnormal or unnested condition of the submunitions.

OBJECTS OF THE INVENTION

[0008] It is the primary object of the present invention to provide for the nesting switch that provides for a reliable indication of the status of the stacked submunitions of an explosive ordnance.

[0009] It is another object of the present invention to provide a nesting switch that occupies a relatively small region to perform its operation.

[0010] It is a further object of the present invention to provide for a fail-safe operating nesting switch.

SUMMARY OF THE INVENTION

[0011] The present invention is directed to a nesting switch having that provides for reliable operations to sense the stacked/unstacked conditions of submunitions of an explosive ordnance, while at the same time requires a relatively small region for its operation, as well as having a fail-safe operation.

[0012] The nesting switch is provided for a launching system for sensing the status of submunitions having a defined storage location within an explosive ordnance. The nesting switch has compression means for being confined within at least one storage location, while at least one of the submunitions is also being confined within its respective storage location.

BRIEF DESCRIPTION OF THE DRAWINGS

[0013] A better understanding of the present invention will be had upon reference to the detailed description when read in conjunction accompanying drawings in which:

[0014]FIG. 1 is a partially cut-away perspective view of nested submunitions, such as grenades, arranged in a stacked matter and held in respective storage locations within an explosive ordnance;

[0015]FIG. 2 is composed of FIGS. 2A and 2B that respectively illustrate a platform that houses a nesting switch in accordance with the present invention and an illustration showing the nesting switch of the present invention arranged with other operative components on a printed circuit board;

[0016]FIG. 3 is composed of FIGS. 3A, 3B, and 3C that cumulatively illustrates one embodiment of the nesting switch of the present invention; and

[0017]FIG. 4 is composed of FIGS. 4A, and 4B that cumulatively illustrates a second embodiment of a nesting switch of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0018] With reference to the drawings wherein the same reference number indicates the same element throughout, there is shown in FIG. 1 a cut-away perspective view of nested submunitions, such as grenades, 10A and 10B arranged in a stacked manner within storage locations confined within a projectile (not shown), which may be an Extended Range Guided Munition (ERGM).

[0019] The ERGM is fired from a naval gun. ERGM, among other sections, has an electronics section and a payload section. The electronics section of ERGM causes the payload section to be ejected from the projectile. Once free of the projectile, the payload section ejects the submunitions. Each submunition has a warhead and a fuze.

[0020]FIG. 1 generally illustrates a nesting switch 12 that is used for sensing the nesting/non-nesting status of the submunitions 10A and 10B, and which has compression means (to be further described hereinafter) for being confined within the storage location while at least one of the submunitions 10A, 10B . . . 10A is within its confined storage location. For the embodiment shown in FIG. 1, the nesting switch 12 comprises at least two terminals 14, that operate in response to the position of a leaf member 16, wherein both the leaf member 16 and the terminals 14 are located on a platform 18. As will be further described, the leaf member 16 either contacts the inner walls 20A of the container 20 holding the submunitions 10A, 10B . . . 10N (nesting event) or does not contact (non-nested event) the inner walls 20A of container 20. The nesting switch 12 provides a reliable method for detecting the stacking (nesting) or unstacking (non-nesting) event of the arrangements of the submunitions 10A, 10B . . . 10N.

[0021] In a normal function scenario related to the explosive ordnances that carry the grenades 10A, 10B . . . 10A, the projectile carrying the explosive ordnance is propelled into flight and the inner battery of the submunition is activated. The typical minimum flight time for the explosive ordnance may be 45 seconds. The maximum flight time for the explosive ordnance may be 8 minutes. Thus, the submunitions 10A, 10B . . . 10N will remain nested together for at least 45 seconds after battery is activated. The nesting switch 12 requires that the submunitions above it to be removed/unnested/unstacked/or separated before the active condition of the nesting switch 12 be performed, that is, the occurrence of the nesting switch be opened. The nesting switch 12 of FIG. 1, may be further described with reference to FIG. 2 composed of FIGS. 2A and 2B.

[0022]FIG. 2A illustrates the fuze 18 as having lodged therein the leaf contact 16, which may be further described with reference to FIG. 2B.

[0023]FIG. 2B illustrates a leaf contact 16 as being located on the fuze 18 and positioned in proximity to the terminals 14. Power for the electronics is supplied by a battery 22. The circuit board 24 has provisions for accommodating electronic components used to operate the submunitions and generally identified in FIG. 2 by reference number 26. The nesting switch 12 may be further described with reference to FIG. 3 composed of FIGS. 3A, 3B, and 3C.

[0024]FIG. 3A illustrates the details of leaf contact 16 having a tab 16A for inserting into complementary opening in fuze 18 and an outer curved portion 16B. The leaf contact 16 further comprises tangs 16C and 16D. The leaf contact 16 is flexible and provides flexible means for either establishing electrical conductivity between terminals 14A and 14B or not establishing electrical conductivity between these terminals 14A and 14B shown in FIG. 3B.

[0025] As seen in FIG. 3B, the leaf contact 16 is in its unnested state and thus, is not in contact with either of the terminals 14A and 14B.

[0026] As seen in FIG. 3C, the nesting switch 12 is in its compressed state whereby its flexible member 16 is in rigid abutment with the inner walls 20A of the container 20 that provides the storage locations holding the submunitions 10A, 10B . . . 10N. In this nesting state, the nesting switch 12 provides electrical conductivity between the first and second terminals indicative that the submunitions are in their nested together stored locations. The leaf contact 16, as well as other flexible members of the nesting switches of the present invention, typically require a compression force of 1-10 lbs. to mate with the terminals 14A and 14B. Furthermore, the tangs 16C and 16D act as assembly aids as the nest switch is inserted through a slot in the circuit board 24. The lower tang 16C is compressed until the circuit board pass and then springs out. The circuit board is captured between the lower tang 16C and upper tang 16D. Moderate amounts of over flexing is allowed to accommodate size tolerance between submunitions 10A, 10B . . . 10N.

[0027] The nesting switch 12, as well as other nesting switches of the present invention may be provided for each submunition 10A, 10B . . . 10N, but at least one nesting switch needs to be provided for any of the submunition 10A, 10B . . . 10N. A further embodiment of the nesting switch of the present invention may be described with reference to FIG. 4 composed of FIGS. 4A and 4B.

[0028]FIG. 4A illustrates a nesting switch 28 as comprised of first and second terminals 30 and 32, respectively, that are separated from each other by a spacer 34 formed of a non-electrically conductive material and having a predetermined thickness, such as 0.030 inch. The spacer 34 is interposed between the first and second terminals 30 and 32, respectively. The terminal 32 acts as a lever, which is stationary within the defined storage locations of the submunitions 10A, 10B . . . 10N, extending outward from the fuze and contacting the inner walls of the container storing the submunitions or the submunition stacked above it.

[0029] The first and second terminals 30 and 32, as well as the spacer 34 are arranged on a fuze 18, as seen in FIG. 4B, so that the first terminal 30 is mounted on the bottom of the fuze 18 and the second terminal 32 is located above the first terminal 30 and separated from the first terminal 30 by the spacer 34. The second terminal 32 is flexible and has a curved outer end 32A. The first terminal 30 extends out from the fuze whereas the flexible second terminal 32 also extends out from the fuze by a predetermined amount, such as 0.030 inch, so that it engages the extended portion of the first terminal 30 when subjected to a predetermined compression force, such as 1-10 lbs. More particularly, when the nesting switch 28 is arranged with a submunition 10A, 10B . . . or 10N, the second terminal 32 rigidly abuts against the inner walls 20A of the container 20 causing the second terminal 32 to become compressed and causing the curved outer end 32A to come into solid contact with the first terminal 30 and, more importantly, causing the nesting indication (electrical conductivity between terminals 30 and 32) to be sent to the electronics 26 of the fuze 18. Moderate amounts of over flexing is allowed to accommodate size tolerance between submunitions.

[0030] It should now be appreciated that the practice of the present invention provides for a nesting switch located on a fuze. The nesting switch in some embodiments have a first contact, which is stationary within the defined storage locations of the submunitions 10A, 10B . . . 10N, and the second contact extending outward from the fuze and contacting the inner walls of the container storing the submunitions 10A, 10B . . . 10N, so that it is deformed causing another part to rotate or otherwise move and make electrical contact. The compression represents a reliable nesting indication that the submunitions are in their desired nested and stacked arrangement. Further, the flexible movement, which consumes a relatively small region, constitutes the space required for the non-operational and operational functions of the nesting switch of the present invention.

[0031] It will be apparent to those skilled in the art that various modifications and variations can be made to the above-described embodiments for the present invention without departing from the scope or spirit of the invention. Thus, it is intended that the present invention cover such modifications or variations provided that they come within the scope of the appended claim and their equivalence. 

What is claimed is:
 1. A switch for a fuze for sensing the status of submunitions having defined storage locations within an explosive ordnance, said switch having compression means for being confined within at least one said storage location while at least one of said submunitions is confined within its respective storage location.
 2. The switch according to claim 1, wherein comprising said switch comprises: at least first and second terminals housed on a platform and electrically connected to said fuze; and flexible means for providing electrical conductivity between said first and second terminals, said flexible means extending out from said platform and contacting at least one of said submunitions in its respective storage location and supplying said electrical conductivity between said first and second terminals representing a nesting indication for said fuze of said stored submunitions.
 3. The switch according to claim 2, wherein said platform and first and second terminals respectively comprise: said platform being dimensioned so as to be confined with said defined storage locations; said first terminal being rigidly located on said platform and being confined within said dimensions of said platform; and said second terminal being merged with said flexible means for providing electrical conductivity between said first and second terminals.
 4. The switch according to claim 1, wherein said switch comprises: at least first and second contacts located on a fuze and each being electrically connected to said fuze, said first contact being stationary on said fuze and located within said defined storage locations of said submunition and said second contact extending out from said fuze and contacting said stored submunition so as to be compressed against said stationary contact while at least one of said submunitions is in its storage location, said compressed stationary and extending contacts being representative of a nesting indication for said fuze of said stored submunitions.
 5. The switch according to claim 1, wherein said compression switch comprises: a platform having a bottom first and second terminals electrically connected to said fuze and housed on top of said platform, said first and second terminals both having portions that extend outward from said fuze with the second terminal's extending portion being flexible and having a length that exceeds said first terminals outwardly extending portion, said flexible portion of said second terminal having a curved portion at its outer end; and a spacer formed of a non-electrically conductive material and interposed between said first and second terminal and having a predetermined thickness so as to establish a predetermined distance between said first and second terminals.
 6. The switch according to claim 1, wherein said submunitions are arranged in a stacked manner and said storage locations are confined within an explosive ordnance.
 7. The switch according to claim 5, wherein said switch is compressed in a location under the lowermost of said storage locations. 